Riverland floodplain becomes a living lab for salt reduction strategies

By Tom FedorowytschUpdated
Mon 19 Aug 2013, 8:48 AM AEST

Photo

Pike River flood plain in SA's Riverland

Tom Fedorowytsch: ABC News

High salinity levels in a wetland in one of the state's oldest irrigation areas have prompted land managers to turn to novel ways to treat soil in the area.

The Pike River floodplain sits between Loxton and Renmark in South Australia's Riverland and was first used by farmers in the nineteenth century.

Large scale irrigation was introduced in the 1960s and the fragile wetland has become increasingly barren because of dry land farming, which drives up the amount of salty groundwater rising to the surface and flowing into the area.

The ecosystem has also struggled to recover from years of drought and the manipulation of water levels.

About 50 local food producers depend on the river for irrigation.

Hopefully, we can pick a winner that we might be able to apply on a much broader scale that will not only be environmentally appropriate but economically feasible.

Brad Hollis, DEWNR

The Department of Environment, Water and Natural Resources is now trialling a range of methods it hopes will restore the briny wetland to health.

Regional infrastructure manager Brad Hollis says, if successful, the Pike River floodplain will not be the only area to benefit.

"We've got a whole range of different treatments that we're essentially wanting to understand better," he said.

"Some of them involve gypsum, some of them involve mulch, some of them just involve watering.

"Hopefully, we can pick a winner that we might be able to apply on a much broader scale that will not only be environmentally appropriate but economically feasible."

Mr Hollis says past approaches to the management of the Murray-Darling basin have done significant damage.

"We're dealing with a very hostile, salt-affected landscape which isn't being helped by the way we're managing our river," he said.

"As a result of the saline ground water levels being kept artificially high we have an accelerated rate of soil salinisation within our River Murray flood plain soil environments, and that essentially means that salt is getting evaporated from the ground water and is concentrating in the soil profile."

The Aboriginal Learning on Country team and the Pike River Land Management Group are also working together on the project.

Local producers have welcomed the trial but believe more time and effort should be concentrated on projects such as the Salt Interception Scheme, which pumps salty water out of the ground before it reaches the river.